1. Field of the Invention
The present invention relates to a sensor for generating electrical signals indicating properties of a mechanical interaction within a sensing zone, and a method of generating electrical signals indicating properties of a mechanical interaction within a sensing zone of a sensor.
2. Description of the Related Art
United Kingdom Patent No. 2 365 532, in the name of the present applicant, discloses a flexible alphanumeric keyboard fabricated from textile fabrics. The construction of the flexible alphanumeric keyboard utilises first and second textile fabric conductive layers. The document teaches the provision of separating means to ensure that the first and second conductive textile fabric layers are normally spaced apart, yet to allow the first and second conductive layers to make contact during a mechanical interaction.
U.S. Pat. No. 5,943,044, in the name of Martinelli et al, discloses a touchpad assembly and method for generating signals indicative of the location and applied pressure of an object touching the touchpad. The assembly of the touchpad includes X and Y position and pressure sensitive semiconductor resistance sensor layers. The position sensor layers are arranged to come into contact at a contact point when the object touches the touchpad.
Problems have been found with sensors that utilise separating means between first and second conductive layers. A production problem with this type of sensor is that a manufacturing overhead exists due to the requirement to provide reliable separating means. A post-production problem with this type of sensor is that false triggering may destroy the functionality of the sensor. These problems are particular prevalent with sensors that are configured to allow a degree of flexing, since the functionality of the separating means tends to degrade more quickly than more rigid sensors.